/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.aop.config;

import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanReference;
import org.springframework.beans.factory.parsing.AbstractComponentDefinition;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * {@link org.springframework.beans.factory.parsing.ComponentDefinition}
 * that bridges the gap between the advisor bean definition configured
 * by the {@code <aop:advisor>} tag and the component definition
 * infrastructure.
 *
 * @author Rob Harrop
 * @author Juergen Hoeller
 * @since 2.0
 */
public class AdvisorComponentDefinition extends AbstractComponentDefinition {

    private final String advisorBeanName;

    private final BeanDefinition advisorDefinition;

    private final String description;

    private final BeanReference[] beanReferences;

    private final BeanDefinition[] beanDefinitions;


    public AdvisorComponentDefinition(String advisorBeanName, BeanDefinition advisorDefinition) {
        this(advisorBeanName, advisorDefinition, null);
    }

    public AdvisorComponentDefinition(
            String advisorBeanName, BeanDefinition advisorDefinition, @Nullable BeanDefinition pointcutDefinition) {

        Assert.notNull(advisorBeanName, "'advisorBeanName' must not be null");
        Assert.notNull(advisorDefinition, "'advisorDefinition' must not be null");
        this.advisorBeanName = advisorBeanName;
        this.advisorDefinition = advisorDefinition;

        MutablePropertyValues pvs = advisorDefinition.getPropertyValues();
        BeanReference adviceReference = (BeanReference) pvs.get("adviceBeanName");
        Assert.state(adviceReference != null, "Missing 'adviceBeanName' property");

        if (pointcutDefinition != null) {
            this.beanReferences = new BeanReference[]{adviceReference};
            this.beanDefinitions = new BeanDefinition[]{advisorDefinition, pointcutDefinition};
            this.description = buildDescription(adviceReference, pointcutDefinition);
        }
        else {
            BeanReference pointcutReference = (BeanReference) pvs.get("pointcut");
            Assert.state(pointcutReference != null, "Missing 'pointcut' property");
            this.beanReferences = new BeanReference[]{adviceReference, pointcutReference};
            this.beanDefinitions = new BeanDefinition[]{advisorDefinition};
            this.description = buildDescription(adviceReference, pointcutReference);
        }
    }

    private String buildDescription(BeanReference adviceReference, BeanDefinition pointcutDefinition) {
        return "Advisor <advice(ref)='" +
                adviceReference.getBeanName() + "', pointcut(expression)=[" +
                pointcutDefinition.getPropertyValues().get("expression") + "]>";
    }

    private String buildDescription(BeanReference adviceReference, BeanReference pointcutReference) {
        return "Advisor <advice(ref)='" +
                adviceReference.getBeanName() + "', pointcut(ref)='" +
                pointcutReference.getBeanName() + "'>";
    }


    @Override
    public String getName() {
        return this.advisorBeanName;
    }

    @Override
    public String getDescription() {
        return this.description;
    }

    @Override
    public BeanDefinition[] getBeanDefinitions() {
        return this.beanDefinitions;
    }

    @Override
    public BeanReference[] getBeanReferences() {
        return this.beanReferences;
    }

    @Override
    @Nullable
    public Object getSource() {
        return this.advisorDefinition.getSource();
    }

}
